Fatigue blood markers

[Andryr]

I need some assistance with understanding why there are no blood fatigue markers. The answer must be obvious but I haven't found any.
Fatigue is a component of many conditions. Hypothyroidism, testosterone deficiency, CFS, EBV, apnea, diabetes etc. Is fatigue the same in any case or does it make difference?
Success stories tell us some were healed with diet change, some with supplements, some with exercise (holy cow, exercise?!). Did they feel the same fatigue? We do not know because we have no blood markers. And why is that? Is it because human organism is too complex?
If I am in a car and I cannot start the engine I will look at the control panel. Dead battery, no fuel, insufficient oil level? There are many reasons but I need to figure it out to start my car.
Would not it be reasonable to go up the stack to understand what is going wrong (fatigue is caused by factor foo which is caused by factor bar which is caused by ...repeat N times... which is caused by some pathogen). Studies seem to be looking for the initial pathogen but are there any looking for the whole chain of consequences? Is anyone looking for the control panel?
I have found some info about fatigue and some cytokines correlation (TNF-a, IL-6, IL-1b, IL-10, IL-2) but that is everything I have. Sorry if I am writing something stupid. Also, forgive my English.

 

[Wishful]

One problem is that many of us probably don't actually have fatigue; we have the neurological perception of a fatigue-like state. I've had many days when I felt like I just wanted to flop down on a bed and rest, yet I knew (and proved) that my body could manage a good 40 km bike ride in hilly terrain. That convinced me that my fatigue-like feelings were neurological. Honest fatigue from physical exertion does feel different.

It probably doesn't take all that many brain cells to be just a bit off normal function to create the perception of a fatigue-like state. It's hard to measure that sort of abnormality in those few cells deep in a brain covered with thick bone. Maybe they could measure it via EEG or functional MRI, but it would probably take a lot of expensive measurements to get enough data from PWME and controls.

 

[ljimbo423]

That convinced me that my fatigue-like feelings were neurological.

I think all fatigue is created in the brain, even muscle fatigue. The brain can interpret signals from muscles as fatigue.

Same with pain, I think signals from the body are sent to the brain, but the brain has to interpret these signals as dangerous, which causes pain. If the brain interprets signals from the body as not dangerous, it doesn't create pain.

I do agree that my fatigue from ME/CFS is not coming from my body, but from my brain. So I don't think blood markers for fatigue can be found.

 

[Wishful]

I think all fatigue is created in the brain, even muscle fatigue.

It's a matter of definition. The perception of fatigue--or pain--takes place in the brain. Where the signal chain starts determines what if anything can be done to treat it. I'm not sure where muscle fatigue signalling starts, but it's outside of the brain.

I wonder whether there's a medical condition in which people are unable to perceive fatigue.

 

[ljimbo423]

I wonder whether there's a medical condition in which people are unable to perceive fatigue.

I don't know about this as it relates to fatigue, but it does happen with pain. Although I think it's rare.

 

[Wishful]

I was vaguely aware of conditions that block pain perception; leprosy blocks a signalling path to the brain. I can't recall a similar disorder for fatigue. That's too bad, since it would be useful for figuring out how fatigue perception works. Maybe such a disorder does occur, but is fatal?